How to find a sentence spread over mutltiple lines in a multiline string

As the title says. I have this string read from a file into a string

"has anyone really been far even as decided to
use even go want
to do look more like"

When I do this, it writes hello world.

    if (string.Contains(@"use even go want
to do look more like"))
    {
        Console.Write("Hello world!");
    }

but when I do this, it won't work.

if (string.Contains(@"use even go want\nto do look more like"))
{
    Console.Write("Hello world!");
}

Isn't there a better way to find a sentence spread over multiple lines in a string instead of just planting a return in the middle of the code?

(I've also already tried \n\r, \r\n and \r)